<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>交换</title>
</head>

<body>
    <script>
        let arr = ['老王', '小郭', '小高', '雪糕老师']
        arr.shift()
        arr.unshift('雪糕老师')
        arr.pop()
        arr.push('老王')
        console.log(arr)
    </script>
</body>

</html>